2 point 4 said:
@Pamela14 - no, just cover them now with whatever compost or soil you have to hand. It can be pre-used - doesn’t have to be good stuff. This is just to stop them drying out any further. Continue to keep them in your shed.During March, uncover the tubers. If they still look dry and withered, give them a soak for a couple of hours before putting in a seed tray as previously described. Once they have got away, pot them on into largish pots whilst you wait for the weather to warm up in May before planting out. Keep them somewhere sheltered in the meantime. Dahlia tubers can get quite dry and shrivelled before they give up the ghost; you only have to look at what they sell in the plastic bags in garden centres sometimes.